Intake module

ABSTRACT

An intake module for an internal combustion engine. The intake module including at least two intake ducts which can be opened and closed by rotatable valves. The valves are connected to one another via a coupling mechanism and to a common actuating mechanism in the form of a servomotor. In order to compensate for tolerances between the valves and the actuating mechanism, the coupling mechanism includes at least one elastic portion, formed by a weakened material portion, which allows the intake valves to be closed and opened completely. The resilience of the coupling mechanism can be brought about by a change in cross-section or a material reduction. In one embodiment of the invention, the coupling mechanism includes multi-part articulated main rods which control the valves by resiliently mounted legs. In another embodiment, the coupling mechanism includes a main rod having branch rods emerging therefrom with a resilient region extending as a relatively thin cross-section of the branch rods over their entire length.

FIELD OF APPLICATION AND STATE OF THE ART

The invention relates to an intake module, especially for internalcombustion engines, having an intake tract with at least two intakeducts and a closing means in each intake duct for affecting the ductcross section.

An intake module of this kind is disclosed in DE 195 03 771 A1 and hasthe advantage declared therein that, by means of a permanently open anda variably closing intake tube opening, the delivery of the combustionmixture to the internal combustion engine can be optimized for theamount of power required. At an appropriate speed of the motor a rotaryvalve is opened and the so-called power duct is opened, whereby amongother things both the fuel consumption and the discharge of pollutantsfrom the motor can be advantageously reduced.

In the known intake module, however, there is the disadvantage that theoperation of the rotary valve controlling the intake duct openings isnot without problems. In the case of the embodiment shown in FIG. 4 ofDE 195 03 771 A1, four rotary valve are connected together excentricallyby a single push rod and can thus be operated. However, due tomanufacturing and component tolerances it is very difficult in thesystem described, and possible only at great cost, to keep all rotaryvalves each in precisely the same position.

Especially to be noted here are the CLOSED and the OPEN position, forhere it is of especial importance that the intake tube opening is eitherfully closed or fully open. For example, it may be possible, due even toslight variations in the length of the push rod, that in the CLOSEDposition actually desired, one rotary valve may not completely close theintake tube opening. As a result a different combustion mixture is fedto one cylinder, resulting in poorer combustion and possibly undesiredside-effects as well as power losses in the motor. For cost reasons,however, an intake module according to the invention is to beinexpensive and accordingly it has to be made without greatcomplication.

The invention is addressed to the problem of creating an intake modulewith closing means in intake ducts of an intake tract, which will avoidthe disadvantages of the state of the art, call for little complexity inmanufacture, and provide reliable operation.

This problem is solved in that at least two closing means can beoperated by common actuating means through coupling means which have atleast one elastic portion for equalizing tolerances between actuatingmeans and closing means. Elasticity and elastic portion are here to beunderstood to mean that they are deliberately provided and preciselydimensioned within a range that is advantageous to the application ofthe invention. Advantageously, they go beyond the elasticity inherent inany workpiece in the case of sufficiently (very) great stress.Accordingly, the force to be applied by the actuating means andproducing the elasticity is within a range common for the purpose. Onthe other hand, the elasticity of the elastic area should not be too“soft,” so that at all times a position of the closing means that isestablished and controllable by the actuating means is assured.

In an embodiment of the invention an elastic link can be providedbetween actuating means, coupling means and/or closing means. This ispossible, for example, through a combination of different materialshaving different properties as regards strength and stiffness. Withspecial preference, however, an elastic portion is in a zone of weakenedmaterial, preferably a thinning, perforation or excavation of material.Thus the strength is reduced at this point and to a certain extent ajoint or flexible portion or elasticity portion is created. Alsopossible is a material modification, as for example local heating orirradiation with UV light which can produce a change or a softening ofthe area in question.

It is possible to make the coupling means of a plurality of pieces, butpreferably they are in one piece, so that the manufacturing and assemblywork can be reduced. In case of a multipartite design of the couplingmeans, identical components can be used or combined advantageously.

In a preferred embodiment, the coupling means have at least one mainrod, which especially has at least one elastic portion. Advantageously,therefore, a main rod can connect directly or indirectly together atleast two closing means, and especially in the case of the transfer offorce it can be made slender along its longitudinal axis and yetsufficiently stable. To reduce the manufacturing cost the coupling meanscan be journaled substantially to the closing means, since theirmounting in the intake ducts is necessary anyway for reliable operation.By this kind of journaling of the coupling means any possibleequalization of tolerances by elasticity between actuating means andclosing means is improved.

The coupling means can have connecting elements by means of which theycan be connected, especially by articulation, to the closing means, theconnecting elements preferably extending approximately vertically fromthe coupling means. Thus the coupling means do not have to run directlyto the closing means. The connecting elements can be in the form ofbranch rods. The vertically reaching connection results in an especiallysimple possibility for arranging an elastic portion which comprises theconnecting elements, which will reach preferably from its beginning toits end. The elasticity in this case consists not in a compression ofelongated coupling means in the longitudinal direction, but is createdby a flexure only of the connecting elements. In this manner an inherentelasticity can be created, especially in the case of connecting elementsconnected stiffly to preferably integrally made coupling means. Thelatter can be more easily flexed in the transverse direction.

In an alternative embodiment it is possible for the connecting elementsto be connected elastically or articulately to a main rod and/or toadditional components of the coupling means, in which case they are madepreferably of rigid shape and the elastic area is provided in theconnection. Such a connection can be made, for example, in a connectingportion having a thin cross section or a cross section formingelasticity.

The closing means used are preferably valves, especially substantiallyround valves which can be rotated about an axis. Such valves are easy tomanufacture and install and, due to their relatively small crosssection, they block only a small part of the flow cross section of anintake duct. Preferably they can be operated through connecting leversand ball joints of the coupling means or connecting elements.

Designing the coupling means together with the connecting elements makespossible a construction in which a part of the coupling means is movedand thrust substantially in the longitudinal direction, while withconnecting elements running out from it closing means at differentdistances from the coupling means can be pivoted.

Preferably, all closing means assume substantially the same position,two positions being especially provided, a CLOSED and an OPEN position,preferably achievable by means of the tolerance equalization, each ofthese positions being determined by abutments for the closing means.Thus individual closing means can be urged toward an end position andadditionally urged by the coupling means in order to urge any closingmeans which are not yet entirely in the same position, likewise againsttheir abutments. Then the force applied by the actuating means to theclosing means or valves can be reduced or removed.

Rotatory actuating means and a substantially translational movement ofthe coupling means are possible, in which case a conversion of therotary movement to longitudinal movement is accomplished through anexcentric pin on the actuating means and a removal opening in thecoupling means, especially substantially in the direction of thelongitudinal axis of the coupling means, the actuating means being ableto be formed by a servomotor plus gearing.

In the case of a multipartite design of the coupling means, it consistspreferably of a plurality of main rods with arms extending therefrom asconnecting elements for closing means in the form of valves. The mainrods can be articulated together, the elastic portion being made, forexample, as a thinning of the material in the connection to the arms,and preferably the operation of two main rods, to each of which twovalves are connected by a third main rod connected to the two main rods.Advantageously the main rods are made substantially identical to reducethe manufacturing and assembly costs.

Alternatively, it is possible to make the coupling means integral with amain rod and branch rods extending vertically therefrom to connect withthe closing means in an intake duct. In that case the elastic portion,as a cross-sectional variation or narrowing of the branch rods incomparison with the main rod, can extend through the entire length ofthe branch rods, the elasticity being achieved by their verticalarrangement. The cross-sectional narrowing can likewise be formed as ajoint only in a limited portion, preferably the connecting portion. Themovement takes place substantially in the direction of the main rod.

The coupling means and/or the connecting elements are preferably made bythe injection molding method, from plastic for example. Especiallypreferred is the use of a thermoplastic provided with differently andvariously oriented cross-sections and profiles according to itsstiffness or elasticity.

To carry gases from the crankcase vent, exhaust feedback or fuel tankventing, an annular gap can be associated with each intake duct. Thisconstitutes a simple kind of gas management.

A seal, preferably of elastic material, is preferably provided on theend of the intake module facing the internal combustion engine to serveas a tolerance equalizing element. By means of this seal, an insertcontaining the valves is urged against the intake module or against theintake duct, and the intake module is urged against the internalcombustion engine, and these connections are hermetically sealed.

The intake module is preferably made of an injection molded plastic orof several injection molded parts. This involves considerable weightadvantages over metal intake modules; furthermore it is easier torecycle.

These and additional features of preferred embodiments of the inventionwill be found not only in the claims but also in the description and thedrawings, and the individual features can be realized each by itself ortogether in the form of subcombinations in the embodiment of theinvention and in other fields, and can constitute advantageous as wellas independently patentable embodiments, for which protection is herebyclaimed. The division of the application into individual sections aswell as section titles do not limit the general validity of thestatements made therein.

BRIEF DESCRIPTION OF THE DRAWINGS

Two embodiments of the invention are represented in the drawings and areexplained more closely hereinafter. In the drawings:

FIG. 1 shows a longitudinal section through an intake module accordingto the invention with multipartite coupling means,

FIG. 2 the arrangement of the valves in the particular duct of an intakemodule,

FIG. 3 a detail of the intake module,

FIG. 4 a cross section through the intake module of FIG. 1 to explainthe mounting of a closing valve with coupling means and valve driver,and

FIG. 5 a perspective view of coupling means made in one piece, withvalves fastened thereon.

DESCRIPTION OF TWO PREFERRED EMBODIMENTS

FIG. 1 shows an intake module 11 pursuant to the invention, in alongitudinal section, wherein only the connectable intake ducts 12 areshown. In these intake ducts 12 are the valves 13 represented in a sideview, which are mounted for rotation on a shaft 14 passing through theircenter in the plane of the valve. In the position shown in FIG. 1, whichis the same for all valves 13, they close the intake ducts completely.

At one end of the shaft 14 is an approximately triangular pivoting crank16 through which the valves can be turned about the shaft. Within thescope of the invention it is also possible to provide the elastic parthere. Thus either the pivoting cranks 16 can be elastic, or elsepreferably the shaft 14 can be equipped with a certain elasticity for alimited torsion, for example through the use of a suitable material orthrough a slimming of the cross section as the elastic part.

Initiation of the movement is made through main rods 17, one of whichconnects together the two left valves and another the two right valves.Then through a third main rod 17, the two outer main rods are joinedtogether, in which case the motion is initiated by this middle main rod.

All three main rods 17 are substantially identical in form, with astraight main portion 18 from whose two ends two short arms 19 projectapproximately vertically as connecting elements. The connection pointbetween the arms 19 and the main part 18 is clearly seen to have areduced cross section serving as the elastic area due to the thinnerportion 20 of its material. In this manner an elastic movement of thearms 19 on the main part 18 is possible within certain limits, which inthis case amounts to a flexure of the arm at the thinner portion 20 asan articulation. At their outer ends the arms 19 are connected to thepivoting cranks 16, as is shown in detail in FIG. 4. Since in the caseof the arrangement represented in FIG. 1, it is substantially onlyforces in the plane of drawing that occur, and these mainly in thedirection of the main portions 18; it is only the elasticity of anelastic portion of the main rods 17, acting in this plane and in thisdirection and serving as coupling means, that is of importance.

The coupling means is driven by a servomotor with gearing, which is notrepresented; on the output shaft 22 (made with a square cross section)thereof a link 23 is placed, which is connected to the main portion 18of the central main rod 17 at a point offset from the output shaft.

Broken lines in FIG. 1 represent the arcs described by the link 23, thesame as in the case of each of the valves 13. It can be seen that acounterclockwise turn of about 90° is possible. The movement of the mainrods 17 in that case is composed of rotational and translationalcomponents, and due to the geometrically identical shapes of the link 23and of pivoting cranks pivoting cranks 16 these parts all performidentical movements. It can be seen that, in case of a 90°counterclockwise rotation, the valves 13 in FIG. 1 will be upright andthus will be approximately in line with the intake duct 12, and open upa maximum free flow cross section. Between the wall of the intake duct12 and that of the intake module 11 an annular gap 24 can clearly beseen, through which crankcase gases or fuel vapors can be fed to themotor.

The main portion 18 of the main rod 17 is made to be rigid with respectto the action of a force in the direction of its length. Like the arms19 with pivoting cranks 16, the main rods 17 are connected to oneanother by ball joints, see FIG. 4. The central main rod 17 differs fromthe outer two only in that the link 23 is pivotally attached to itapproximately at its center.

In FIG. 2 the intake module 11 is shown in section, the plane of sectionpassing through the center of the valves 13. Here, again, the valves areshown in the CLOSED position.

FIG. 3 shows a detail of the intake module 11 which is welded to abracket 39. In the intake module 11 there is a sleeve 41, preferably ofmetal, by which the intake module can be fastened to the cylinder headof an internal combustion engine. Crankcase gases which are to bereturned to the combustion chamber enter through the opening 42, arecarried through opening 43 into the cavity of the sleeve 41 and flowfrom there through the opening 44 into a distribution duct 45. From thedistribution duct 45 they pass, as shown in FIG. 2, into the annulargaps 24.

FIG. 4 shows the intake module of FIG. 1 in cross section, the valve 13being in the OPEN position, in contrast to FIG. 1, and the intake duct12 has as large an internal cross section as possible. The round shapeof the valve acting as the closing means is clearly to be seen. Theshaft 14 is journaled at both ends in plastic bushings 26 which canconsist preferably of self-lubricating plastic, such as POM(polyoxymethylene), for example. At its end projecting through theplastic bushing 26 and provided with a square cross section there isattached the pivoting crank 16. It has a projecting pin with a sphericalextremity 27 which is engaged in a ball joint socket 28 of the arm 19.As it can be seen from the profile top view of the main rod 17, thelatter tapers from the main portion 18 to the arm 19. Thus an elastic oryielding configuration of the main rod 17 can also be achieved here.

From the main rod 17, which joins two valves 13 to one another, anadditional ball-end pin 27 extends, which in turn is engaged in a balljoint socket 28 of the arm 19 of the central main rod 17. In this mannerthe valves 13 are each connected through the pivoting cranks 16 to themain rods 17, so that tolerance equalizing movements are possible notjust in the plane of FIG. 1. The central main rod 17 is driven by aservomotor, not shown, through a connecting pin 30 on the link 23. Theentire operating mechanism is integrated in a housing and thus is notexposed to dirt or to any gases, so that high reliability of operationis achieved.

On the bottom side of the intake module 11 a seal 31 is provided whichsurrounds the intake duct 12 to serve as a tolerance equalizing elementbetween a valve mounting 33, which contains the plastic valve bearings26, and the base structure or housing 32 of the intake module 11. Inthis manner a closing means holder is possible which can be insertedinto the housing 32 and can be closed or steplessly opened especiallywell by a round valve 13. This offers the advantage that, in contrast tothe rest of the housing 32 of the intake module 11 and to the intakeduct 12, only the valve mounting 33 needs to be made with closecomponent tolerances in order to achieve a reliable closure by the valve13.

In a variation of the construction of the coupling means represented inFIGS. 1 and 4, there is shown in FIG. 5 a one-piece embodiment in adiagonal perspective view, but one which can easily be replaced by theother version. It consists of an elongated main rod 17 from which threebranch rods 35 extend subtantially horizontally, to the rear on the leftand to the front on the right. Both the main rod 17 and the branch rods35 have a constant cross section, which, as it can be seen in the caseof the main rod, can be in the form of cross ribbing, for example.

The elasticity in the branch rods is achieved only by the selection ofan appropriate cross section which remains equal through the entirelength from the connection to the main rod to the ball joint bearingbushes, the rearwardly extending branch rods have a different crosssection than the ones extending forward. The cross section and length ofthe branch rods 35 are made such that all ball joint bearing bushes 28at the ends of the branch rods have the same elasticity with respect tothe main rod 17. In reference to FIG. 5, this signifies that therearwardly extending branch rods have a lesser elasticity on account oftheir decidedly shorter length and thus a cross section providing agreater elasticity than the forwardly reaching branch rods. The latterare longer, and for this reason their cross section is stronger and lesselastic, due for example to cross ribbing that increases stiffness. Anadditional control or increase of the elasticity can be achieved by thebend made at a certain angle in the shape of the branch rods 35, whichin the case of the short branch rods amounts to about 90° and in thelong ones to about 135°.

In a manner similar to the preceding figures, pivoting cranks 16 arefastened by means of ball-end pins 27 in the ball joint bearing bushes28 which are situated on shafts 14 of valves 13. As it can be seen inFIG. 5, the valve 13 and shaft 14 can be integral or made of a singlecasting, possibly even with the pivoting crank 16 formed thereon. Toincrease the stiffness of the valves 13 reinforcing ribs 16 areprovided.

FIG. 5 shows the mounting of a valve 13 in a valve mounting 33 whichconsists of a plastic material described above and can be in the shapeof, say, a section of pipe. On its right portion can be seen one of theplastic bearing bushes 26 in which the right end of the shaft 14 isjournaled. It has a rather bead-like abutment 38 which projects from itsinner wall and forms a semicircle between the bearing bushes 26. Thevalve 13 strikes it from the bottom, so that in this case an actuationof the coupling means to the right takes place in the clockwisedirection. The abutment forming the other semicircle is then situatedbelow the valve so that the valve lies on top of it. The valve in thisposition against these abutments shuts off the intake duct. The valvemounting 33 is inserted into the housing 32 of the intake module 11 andis preferably sealed against it by a gasket 31.

In order to be driven, the main rod 17 has at its right end an opening37 into which a link pin 30 or an eccentric pin of a driver enters tooperate it. The movement of the main rod 17 and of the pivoting cranks16 and valves 13 is performed in a manner similar to that described inFIG. 1.

Operation

For assembly, the valve mountings 33 containing the valves 13 areinserted into the intake ducts and into the housing 32 of the intakemodule 11. The main rods 17 are attached by means of the ball joints tothe pivoting cranks 16 formed on or attached to the shafts 14 of thevalves 13, this operation being largely the same in both of theembodiments according to FIG. 1 and FIG. 5. Then the coupling means areconnected to the operating drive, for example through a link pin 30which enters into an opening 37 on the coupling means or on a main rod17. Thus, the coupling means or the main rod 17 with arms 19 and branchrods 35 are linked only to the valves 13 and possibly also to the linkpin 30 of the operating drive; no further connections are necessary.

The rotatory operation of the drive is converted to a movement of themain rods 17 that consists substantially of rotary and translationalcomponents, the ball joint bearing bushes 28 situated at the ends of thearms 19 and branch rods 35 describe an arc corresponding to the movementof the link pin 30. This is followed by a purely rotatory movement ofthe pivoting cranks 16 and of the valves 13 connected with them throughthe shaft 14. This arc extends preferably over 90°, the two maximum endpositions being a CLOSED position and an OPEN position, respectively. Inthe valve mountings 33 abutments may be present which prevent the valvesfrom turning past either of the two end positions.

The invention can be advantageously combined with such abutments since,for example, valves 13 that are in a position slightly ahead of theothers reach the end position established by the abutments first, whileall valves that can be rotated further by the continued movement of thecoupling means can then also run against the abutments to their endpositions. Further movement of the coupling means after one valve hasalready arrived against the abutment is made possible by the elasticityprovided by the invention between closing means or valves 13 and theactuating means or drive. The elasticity thus equalizes the tolerancesbetween the positions and abutments of the end positions of the valves.Thus the valves 13 do not have to be at every moment precisely in thesame position, since this position is automatically achieved in the twoimportant positions, the CLOSED and the OPEN position by the toleranceequalization resulting from the elasticity.

An alternative way of obtaining the elasticity might also consist in anelasticity produced along the translational movement of the couplingmeans, for example in the form of a longitudinal springing of the mainrod 17. What would be possible in this case is a telescoping resilientarrangement. The great advantage of the embodiments of the couplingmeans represented in FIGS. 1 and 5 is, however, they are achievedwithout additional springs or resilient elements, since the elasticityis in each case inherent in the coupling means. Especially advantageousis the embodiment of FIG. 5, since the coupling means can be made in onepiece, thereby facilitating installation.

What is claimed is:
 1. An intake module comprising: at least two intakeducts; a rotatable valve operatively arranged in each intake duct toopen and close each respective intake duct by rotating about a shaftwhich defines a rotation axis; and a common actuating mechanismoperatively arranged to actuate the at least two rotatable valvesthrough a coupling mechanism comprising pivoting cranks; wherein thecoupling mechanism comprises at least one elastic portion formed by aweakened material portion which provides tolerance equalization betweenthe common actuating mechanism and the at least two rotatable valves. 2.Intake module according to claim 1, wherein the at least two valves,shafts and pivoting cranks are multipartite.
 3. Intake module accordingto claim 1, wherein each valve, shaft and pivoting crank forms a onepiece assembly.
 4. Intake module according to claim 1, wherein thecoupling mechanism comprises at least one main rod which comprises theat least one elastic portion.
 5. Intake module according to claim 3,wherein the coupling mechanism comprises a one-piece arrangementcomprising connecting elements comprising branch rods each beingoperatively connected to the at least two valves, the connectingelements extending substantially horizontally.
 6. Intake moduleaccording to claim 5, wherein the branch rods form the elastic portionsof the integrally formed coupling mechanism.
 7. Intake module accordingto claim 6, wherein the connecting elements are connected elastically toa main rod of the coupling mechanism, the connecting elements beingrelatively stiff and the elastic portions being formed at a connectionof the connecting elements to the main rod.
 8. Intake module accordingto claim 1, wherein all of the at least two valves assume substantiallythe same position during operation by way of the at least one elasticportion, the positions of the at least two valves comprising a CLOSEDand an OPEN position, each CLOSED and OPEN position being determined byabutments.
 9. Intake module according to claim 1, wherein by way of arotationally working actuating mechanism and a substantiallytranslational movement of the coupling mechanism, the coupling mechanismis moved substantially in a direction of a longitudinal axis of thecoupling mechanism through an eccentric pin or linking pin on theactuating mechanism and an opening on the coupling mechanism.
 10. Intakemodule according to claim 3, wherein the coupling mechanism comprises aplurality of main rods having arms extending out from the main rods andoperating as connecting elements for connection to the valves, the mainrods being articulated to one another and the at least one elastic areacomprising a material thinning of a main rod and being situated in anarea of the connection with the arms, and the operation of two main rodsto each of which two valves are connected is performed by a third mainrod connected to the two main rods, the main rods being substantiallyidentical.
 11. Intake module according to claim 4, wherein the couplingmechanism is made in one piece including a main rod and branch rodsprojecting substantially horizontally therefrom for connection with theat least two valves, the at least one elastic portion being configuredas a cross-sectional narrowing of the branch rods, and the couplingmechanism being operated by a servomotor with an eccentric pin on thedrive end of the main rod, and an opening formed thereon and disposedperpendicular to the main rod.
 12. Intake module according to claim 5,wherein the coupling mechanism is made by an injection molding methodfrom plastic.
 13. Intake module according to claim 1, wherein eachintake duct includes an annular gap to which gases are delivered fromone of a crankcase vent, an exhaust gas return, and a fuel tankventilation.
 14. Intake module according to claim 1, wherein on an endface of the intake module facing an internal combustion engine a gasketis provided as a tolerance equalizing element between a housing of theintake module and a valve mounting as an insert in an intake duct. 15.Intake module according to claim 6, wherein the connecting elements areconnected articulately to a main rod of the coupling mechanism, theconnecting elements being relatively stiff and the elastic portionsbeing formed at a connection of the connecting elements to the main rod.16. Intake module according to claim 5, wherein the connecting elementsare made by an injection molding method from plastic.